高端锐截止的短截线超宽带滤波器

对传统短截线超宽带滤波器作了改进：首先,各短路短截线的长度不限定为1/4波长,且互相之间有差异,这就使得原本集中于2f0的N个传输零点在一定阻带范围内分散并优化分布;其次,在每个1/4波长连接传输线的中点位置加载一定长度和特性阻抗的开路短截线,从而在高频阻带范围内产生了若干新的传输零点。通过软件优化,高频阻带出现了等波纹抑制特性。该方案使得短截线滤波器的通带高端锐截止,且高频阻带的带宽变宽。实测结果证明了该方法的有效性。

Ultra-wideband(UWB) Stub Filter with Steep Rejection Slope at the High Edge of Passband

In this paper,traditional ultra-wideband stub filters are modified to have more transmission zeros with optimized distribution to achieve sharp rejection slope at the high edge of passband.Firstly,the short-circuited stubs are set to have different lengths and the corresponding transmission zeros are no longer fixed at 2f0,but distributed optimally.Secondly,every 1/4λ connecting line is loaded with an open-circuited stub of certain length to introduce one transmission zero.The design of a three-order filter is conducted by optimization.The measured responses have well validated the feasibility of the methods.